Stencil sheet



Patented Aug. 3, 1926.

UNITED STATES SHINJ'IRO HORII, F TOKYO, JAPAN.

STENCIL SHEET.

No Drawing.

This invention relates to improvements in stencil sheets of the type commonly used for autographic and typewriting duplication, consisting of a sheet of fibrous material 5 coated or impregnated with a composition comprising esters of polysaccharides, naph- .thenic acids for the purpose of preparing the superior stencil sheets which offer a considerably great resistance to the atmospheric influences on using or storing, and give a larger number of clear and sharp copies.

It is ell known that a solution of collodion or celluloid, combined with castor oil or other fatty oils as a tempering agent,

has been used for a coating material to produce stencil sheets. Such a composition does not, however, produce a superior stencil sheet, having the disadvantages of being sticky on handling and, moreover. the

coated medium is not soft enough to give a clear writing by the abrasion of a stylus or by the impact of the type of a writing machine.

It has been found that it is possible to incorporate uniformly. the cellulose esters into naphthenic acids, and that the composition comprising esters of polysaccharides, combined with naphthenic acids is the most superior coating material for stencil sheets,

which. gives a coating of the desired uniform softness but without the stickiness and is not brittlefin cold weather. The stencll sheets thus obtained can be used throughout an extended period of time without any change on the coating and produce therefrom a large number of clear and sharp copies.

In carrying out the invention a sheet of fibrous material, for instance Yoshino paper,

is coated or impregnated with a coating solution prepared by dissolving esters of polysaccharides, such as starch acetates, cellulose acetates, cellulose nitrates and cellulose Xanthate, in suitable solvents, such as alcohols, aceton, theylacetate, amylacetate ether, and adding naphthenic acids. To the above -App1icatiou filed December 3, 1925. Serial No. 73,060.

Naphthe-nic acids 10 Japan wax 5 59 Methanol 15 Aceton i 15 Amylalcohol -i 30 As stated the coated sheets remain 5 throughout an extended period of time practieally unchanged without the drawback of becoming sticky or friable on handling or storing. By the abrasion of a stylus or the blow of the type of a typewriter, without '7 necessity of moistening the sheets with water or moistening solutions, the clear characters may be easily produced thereon.

The term esters of polysaccharides is intended to include not only one of definite esters of polysaccharides, but also a mixture of them.

-lVl1at I claim is 1. A stencil sheet adapted for stencili zin by pressure, comprising a base of fibrous material impregnated With a composition including esters of polysaccharides, and naphthenic acids.

2. A stencil sheet adapted for stencilizing by pressure, comprising a base of fibrous material impregnated with a composition including, e ters of polysaccharides, naphthenic acids and tempering agents, such as fatty acids, fatty oils, fats and waxes.

In testimony whereof I aflix my signature.

SH N J IRO HORII 

